Carburetor with fluid elements

ABSTRACT

A carburetor employing three pure fluid amplifiers for controlling the flow of fuel to a cylinder. Fuel from a source is supplied to the power input of a first amplifier. The power outputs of this amplifier are connected to the power inputs of the other two amplifiers. The fuel supplied to the two amplifiers may be controlled by the amplifiers to flow to the cylinder and/or to return to the fuel source. Pressure within the cylinder is sensed to control the fluid amplifiers whereby fuel is supplied to the cylinder from one of the two amplifiers during idling or partial power output and fuel is supplied to the cylinder from both of the two amplifiers during full power output.

United States Patent Appl. No. Filed Patented Assignee PriorityCARBURETOR WITH FLUID ELEMENTS 9 Claims, 8 Drawing Figs.

US. Cl 261/36, 123/119.261/69,261/41,137/8l.5

Int. Cl F02m 7/06 Field ofSearch..... 261/361, 69,69.l,4l; 137/8l.5;123/119 References Cited UNITED STATES PATENTS 6/1965 Bauer PrimaryExaminer-Tim R. Miles Attorney-Griffin, Branigan & Kindness ABSTRACT: Acarburetor employing three pure fluid amplifiers for controlling theflow of fuel to a cylinder. Fuel from a source is supplied to the powerinput of a first amplifier. The power outputs of this amplifier areconnected to the power inputs of the other two amplifiers. The fuelsupplied to the two amplifiers may be controlled by the amplifiers toflow to the cylinder and/or to return to the fuel source. Pressurewithin the cylinder is sensed to control the fluid amplifiers wherebyfuel is supplied to the cylinder from one of the two amplifiers duringidling or partial power output and fuel is supplied to the cylinder fromboth of the two amplifiers during full power output.

PATENTEUJAN 1 919?:

Fig.2

Fig. I

CARBURETOR WITII FLUID ELEMENTS PRIOR ART FIG. 1 shows a typicalcarburetor of the prior art employing a fluid amplifying element. It ismade up of a fluid amplifying element 1, a fuel pump 2, a fuel tank 3, acylinder 4 and a throttle valve 5. In this carburetor, the (fluid)circuit, which is connected to both terminals of the control circuit C land C of the fluid amplifying element 1, is so arranged that it opens toboth upstream and downstream ports 6 and 7 of the throttle valve in thecylinder 4. The three power output terminals P P P of the fluidamplifying element 1 are respectively connected to the (fluid) circuitswhich open into the fuel tank 3, the ports 8 and 9 of the cylinder 4.This type of carburetor uses only one fluid element, and the fuelflowing out of the power output outlets of the fluid element is the onlyfuel which is used during both the idling and the full operation of theengine. Therefore, this carburetor cannot fully satisfy the fuelrequirement of the engine, which varies very widely, i.e., the quantityof fuel required during idling is very small but during full operationis very large. In order to overcome this deficiency, various auxiliaryequipment has to be added to the carburetor. Furthermore, massproduction of this type of carburetor is difficult.

SUMMARY OF THE INVENTION An object of the present invention is toprovide a carburetor employing plural fluid amplifying elements, saidcarburetor having none of the disadvantages of the prior art.

An object of the present invention is to provide a carburetor having aprimary fluid amplifier and a secondary fluid amplifier, the amplifiersbeing interconnected whereby fuel from a supply source is appliedthrough the primary and then the secondary amplifier to a cylinder, andmeans for controlling the amplifiers in response to the pressure in thecylinder.

An object of the present invention is to provide a carburetor employingfirst and second secondary fluid amplifiers, a primary fluid amplifierfor proportioning the flow of fuel from a source to each of thesecondary amplifiers, a cylinder, means for sensing the pressure in saidcylinder for controlling all of the fluid amplifiers whereby the firstsecondary amplifier feeds fuel to the cylinder during periods of idlingand partial power output and both the secondary amplifiers feed fuel tothe cylinder during periods of full power output.

An object of the invention is to provide a carburetor as described aboveand including a further control means for the second secondaryamplifier. In one embodiment, the control means comprises a fluid valveactuated by a mechanism that moves a throttle valve in the cylinder. Inanother embodiment, the control means comprises a mechanical valveoperated by the pressure in the cylinder downstream of the throttlevalve.

BRIEF EXPLANATION OF THE FIGURES FIG. 1 shows the pipe arrangement of awell-known carburetor with fluid elements;

FIG. 2 is a fluid element;

FIG. 3 shows the pipe arrangement of the carburetor;

FIG. 4 is a longitudinal section of the pressure regulator used in thecarburetor shown in FIG. 3;.

FIG. 5A and B show the structures of other types of pressure regulators;

FIG. 6 is a longitudinal section of a pressure regulator having astructure different from that of the regulators mentioned above; and

FIG. 7 is a diagram showing the characteristic capacities of thecarburetor described in FIG. 3.

This invention will be explained by the use of FIG. 2 to FIG.

outlets divided by the splitter 10. C and C are the terminals of thecontrol circuit connected to the control nozzle. When high energy fluidis supplied to the supply port Pro at the fluid element 10, shown inFIG. 2, and if there is no input signal at the control circuit terminalsC and C most of the high energy fluid supplied will rush directly to thepower output outlet I because the main jet connected to the supply portP and the inlet connected to the power output outlet P are located onthe straight line connecting Pm and Pig as judged from the shape of thesplitter 10' shown in thc.FlG. Only a small quantity of the remainingfluid which has not been split completely is pushed through the poweroutput outlet P As for the input signal, when (low energy) fluid flowsfrom one terminal of the control circuit C to the other terminal C themain jet flow is deviated and the output is gradually transferred fromone power output outlet P 0 the other power output outlet P depending onthe size of the input signal given. In this way, the fluid elementexerts its amplifying action by controlling the high energy fluid by theuse of the low energy fluid. In FIG. 3, three elements 10, and 30 areused as the fluid element.

In FIG. 3, the symbols used are the same as those used in I FIG. 2. Forthe symbol of the control circuit terminals, C is pump starts to operatefirst, the fuel flowing out of the fuel 6. FIG. 2 is an enlarged FIG. ofthe first fluid element 10 used with the number of tlie fluid elementand the number of the control circuit terminal as its subscripts. Forthe power output outlet, the symbol P is used with the fluid elementnumber and the number representing the power output terminal as itssubscripts. The element 30 is the same as the element 10, but theelement 20 is different in that it contains three power output outlets.As shown in FIG. 3, the control circuit terminals of each element, C Cand C are connected to the pipe which opens to the port 6 located at theupstream of the throttle valve in the cylinder 4. The control circuitterminals C and C of the elements 10 and 20 are opened to theatmosphere, and the control circuit terminal C of the element 30 isconnected to the pressure regulator 15 through the pipe 17. The pressureregulator in turn is connected to the one terminal of the pipe 16, theother terminal of which opens to the port 7 located at the downstream ofthe throttle 5. Therefore, the control circuit terminal 32 will receivethe manifold vacuum of the port 7 at the downstream of the throttle 5through the pressure regulator 15. One of the three power output outletsP of the element 20 is connected to the fuel tank 3 through the returncircuit 13; the output opening P is connected to the pipe which opens tothe idle port 11 located at the downstream of the throttle, and theother output outlet P is connected to the pipe which opens to the port8. 12 is the idle adjusting screw which regulates the quantity of fuelsupplied from the power output outlet P to the idle port 11 duringengine idling. The structure of this ad justing screw is the same asthat of the adjusting screw used to control the amount of fuel suppliedto the idle port of the conventional carburetor without the fluidelement.

The operation of the carburetor shown in FIG. 3 will be explained next.When the engine is not in operation and the fuel pump 2 will return tothe fuel tank 3 from the power output outlet P of the fluid element 10through the power output. outlet P of the fluid element 30. Theremaining fuel, which has not been separated completely in the directionof the power output outlet P of the fluid element 10, will return to thefuel tank 3 from the power output outlet I through the power outputoutlet P of the fluid element 20 and the retum circuit 13. Therefore, nofuel is supplied to the cylinder 4 at this moment. When the enginestarts to operate, a slight negative pressure will form at the port 6connected to the control circuit terminal during the idling, and thusthe negative pres sure will appear as an input signal on the controlcircuit terminals ll, 21, and 31 of the respective fluid elements I0, 20and 30. However, the negative pressure from the port 7 at the downstreamof the throttle will appear on the other control circuit terminal C ofthe fluid element 30, and thus the fluid element 30 will not operate. Inthis case, the fluid elements 10 and 20 will operate first. In otherwords, the output of the fluid element 10, which has appeared almostcompletely at the power output outlet P will now be slightly shifted tothe other power output outlet P, and thus the quantity of fuel suppliedto the fluid element 20 is increased. In the fluid element 20, the fuelwhich has appeared almost completely at the power output outlet P due tothe input signal. i.e., the negative pressure on the control circuitterminal C will also be transferred to some extent to the power outputoutlet P Furthermore, the suction vacuum of the engine will cause theformation of strong vacuum at the power output outlet P Consequently,the fuel is more easily transferred to the output outlet P and issupplied to the idle port 11.

When the throttle 5 is opened and the engine is in the state of partialpower output, the vacuum input signal of the control circuit terminals Cand C will become bigger due to the vacuum at the port 6. Subsequently,more fuel from the power output outlet P will be supplied to the fluidelement 20, and the output fuel of the fluid element will be transferredfurther from the power output outlet P to the other power output outletP Therefore, sufficient quantities of fuel can be supplied to the port8.

The formation of the controlling vacuum depends on the amount of airsucked in by the engine, and the fuel flow may shift from the poweroutput outlet P to P or'undergo successive shift from P to P to Pdepending on the pressures. In this way, the appropriate quantity offuel for partial power output can be supplied to the port 8 of thecylinder from the power output outlet P through the partial power outputnozzle 18.

As in the case of idling, the vacuum at the one control circuit terminalC of the fluid element 30 is larger than that at the other terminal Cduring the partial power output of the engine. The output fuel of thefluid element 30 therefore is always shifted to the direction of thepower output outlet P .and is returned to the fuel tank 3 via the returncircuit 14.

Even though the quantity of air sucked in by the engine is increased andthe negative pressure at the port 7 becomes extremely large, thecontrolling vacuum at the control circuit terminal C will not exceed thepreset value because of the action of the pressure regulator 15.Therefore, during the full power output of the engine, the controllingvacuum at the control circuit terminal C caused by the port 6 is largerthan that at C and the output fuel of the fluid element 30 is shiftedfrom the power output outlet P to P3,. Consequently, the fuel will alsobe supplied to the engine from the full power output nozzle 9 whichopens at the port 19.

The structure of the pressure regulator is shown in FIG. 4.

The main body 21 contains the openings 16 and 17"connected respectivelyto the pipes 16 and 17 mentioned above, and also the ventilation hole 22connected to atmospheric air. It is also equipped with regulating screws23 and 24 which adjust the throttle resistance of the opening 17 and theventilation hole 22. When this pressure regulator is installed on thecarburetor shown in FIG. 3, the vacuum at the port 7 located at thedownstream of the throttle valve is lowered by at as mentioned beforeduring the full power output with the' manifold vacuum greater than 60mm. Hg. Consequently, the fuel can also be supplied from the full poweroutput nozzle 19 depending on the quantity of air sucked in by theengine (namely, suction vacuum).

FIG. 5 shows another type of pressure regulator. This regulator does notregulate the pressure directly. Rather, it acts like a switch valve andexerts the same regulating effect as that of the pressure regulatorshown in FIG. 4. As shown in FIG. 5,

the main body contains the opening 17 connected to the pipe 17 shown inFIG. 3 and the ventilationhole 22 connected to atmospheric air. Thepiston 26 connected to the cam interlocked with the throttle valve 5 islocated within the main body 21 and can be moved freely. The spring 27always presses the piston 26 against the cam 25. The piston 26 has athrough hole 26 which can be connected to either the opening 17 or theventilation hole 22 asshown in FIG. 5(B), depending on the position ofthe piston 26. One can adjust the relative position of the cam 25 andthe throttle valve 5 in such a way that when the opening of the throttlevalve exceeds the preset degree of opening, the cam 25 vvilI cause theopening 17 to be connected to the ventilationhole 22 as shown in FIG.5(B). When the opening of the throttle valve is below the preset degreeof opening, the piston 26 will shut off the connection between theopening 17' and the ventilation hole 22 as shown in FIG. 5(A). In thisway, the fluid element 30 will start to operate only during the periodof the full power output in which the opening of the throttle valveexceeds the preset degree of opening as mentioned above, and the fuel isalso supplied through the full power output nozzle.

FIG. 6 shows the structure of another device whose function is the sameas that of the pressure regulator 15. The piston 28 is always pushed tothe right by the spring 29. The manifold vacuum at the opening 16,connected to the pipe which opens at the port 7 located at thedownstream of the throttle valve, will suck the piston 28 to the left toshut off the opening 17' which was originally connected to atmosphericair via the through hole 28. If the force of the spring 29 is soadjusted by the use of the regulating screw 31 that the piston 28 willbe sucked to the left to shut off the opening 17' when the manifoldvacuum is about 60 mm. Hg, the piston 28 will be pushed to the right bythe reaction of the spring 29 during the period of full power output,and the opening 17 .is connected to atmospheric air. Subsequently, thefluid element 30 will start to operate and the fuel is also suppliedfrom the full power output nozzle.

The pressure regulators (or pressure regulators which act like a switchvalve) shown in FIGS. 4 to 6 can regulate the input signal applied onthe control circuit terminals of the fluid element 30 in accordance withthe quantity of air sucked in and the degree of opening of the throttlevalve. It is also possible to operate the pressure regulatorselectrically by the use of widely-known devices.

Instead of adjusting the input signal (controlling vacuum) placed on thecontrol circuit terminal by the action of the fluid element during theperiod of full power output, the expected result could also be obtainedby the procedures mentioned below. One control circuit terminal C of thefluid element 30 is connected to atmospheric air, and a switch valve isinstalled on the passage between the power output outlet P and the fullpower output nozzle 19. The degree of opening of the throttle valve orthe manifold vacuum is then so adjusted that the switch valve will openonly during the period of full power output.

The controlling vacuum of all elements is obtained from the vacuumoutlet which opens to the common port 6. It is also possible to havedifferent vacuum outlets for each element with different controllingvacuums.

Adjustable throttling devices such as idle adjusting screws or jets canbe installed on part or on the entire portion of the passage between thepower output outlet P of each element and the control circuit terminalsC to achieve the microadjustment of the quantity of fuel supplied to theengine.

The fuel characteristics of the carburetor shown in FIG. 3 are given inFIG. 7. During the period of idling and partial power output in whichthe vacuum at the cylinder is relatively small, the fuel is suppliedalmost entirely from the power output outlets P and P of the element 20.During the period of full power output, the power output outlet 31 ofthe element 30 can also supply the fuel additively to the engine, andthus the engine is sufficiently supplied with the fuel.

In the carburetor shown in the FlGS., the first fluid element used hasthe structural capacity of supplying almost all the output fuel from onepower output outlet P in the absence of the input signal. However, fluidelements with a main jet or splitter, by which the output fuel can besupplied almost equally from the two output openings P and P in theabsence of the input signal, can also be used.

The carburetor invented can supply a very small quantity of fuel duringidling and a very large quantity of fuel during the period of full poweroutput. The fluid amplifying elements used in the carburetor canautomatically control the quantity of fuel flow within a very wide rangeas required by the engine. The cost of manufacture of the carburetor islow and its mass production is feasible. The fluid element used has along life.

We claim: 1. A carburetor for an internal combustion engine, saidcarburetor comprising:

a primary fluid amplifier through which all fuel must flow to reach saidengine;

said primary fluid amplifier having a power input for receiving saidfuel, first and second power outlets, and a control input forselectively proportioning the fuel received at said power input betweensaid power outlets;

first and second secondary fluid amplifiers, said secondary amplifierseach having a power input, first and second power outlets, and a controlinput for selectively proportioning fuel received at said power inputbetween said power outlets;

first means connecting the first and second power outlets of saidprimary amplifier to the power inputs of said first and second secondaryamplifiers, respectively;

a cylinder;

second means connecting the second power outlet of each secondaryamplifier to said cylinder; and

third means for sensing the pressure in said cylinder and conveying anindication of said pressure to the control inputs of said primaryamplifier and said secondary amplifiers.

2. A carburetor as claimed in claim 1 wherein:

the internal configuration of said primary amplifier is such that amajor portion of the fuel received at its power input is directed to itssecond outlet during periods of engine idling when the pressure sensedin said cylinder is at its maximum, a minor portion being directed tothe first power outlet of said first amplifier; and

said primary amplifier directing proportionately more of said fuel toits first power outlet as the pressure in said cylinder decreases.

3. A carburetor as claimed in claim 2 wherein fuel flow into said firstsecondary amplifier is divided and flows out its first and second poweroutputs during periods of engine idle, said carburetor furtherincluding:

a throttle valve in said cylinder;

said second means including a fluid passage connecting the second poweroutlet of said first secondary amplifier to said cylinder downstream ofsaid throttle valve; and

idle adjusting means for controlling the flow of fluid through saidpassage.

4. A carburetor as claimed in claim 3 wherein said first secondary fluidamplifier includes a third power outlet, said power outlets beingpositioned with respect to the power input and control input wherebymore fuel is delivered to said second and said third power outputs aspressure in said cylinder decreases.

5. A carburetor as claimed in claim 3 and further comprising:

a second control input for said second secondary amplifier;

and

further means for applying a signal to said second control input.

6. A carburetor as claimed in claim 5 wherein said further meanscomprises a fluid passage means terminating at an opening in saidcylinder, and pressure regulating means in said fluid assa e means.

7. car uretor as claimed in claim 5 wherein said further means comprisea normally closed fluid valve, and means mechanically linked with saidthrottle valve for operating said fluid valve, said fluid valve, whenoperated, connecting said second control input to the atmosphere.

8. A carburetor as claimed in claim 5 wherein said further meanscomprise means for sensing the pressure downstream from said throttlevalve, and valve means responsive to said last named means forconnecting said second control input to the atmosphere.

9. A carburetor as claimed in claim 5 and further comprising:

a source of fuel;

means connecting said source to the power input of said primaryamplifier; and

means connected to said first power outputs of said secondary amplifiersfor returning fuel to said source.

1. A carburetor for an internal Combustion engine, said carburetorcomprising: a primary fluid amplifier through which all fuel must flowto reach said engine; said primary fluid amplifier having a power inputfor receiving said fuel, first and second power outlets, and a controlinput for selectively proportioning the fuel received at said powerinput between said power outlets; first and second secondary fluidamplifiers, said secondary amplifiers each having a power input, firstand second power outlets, and a control input for selectivelyproportioning fuel received at said power input between said poweroutlets; first means connecting the first and second power outlets ofsaid primary amplifier to the power inputs of said first and secondsecondary amplifiers, respectively; a cylinder; second means connectingthe second power outlet of each secondary amplifier to said cylinder;and third means for sensing the pressure in said cylinder and conveyingan indication of said pressure to the control inputs of said primaryamplifier and said secondary amplifiers.
 2. A carburetor as claimed inclaim 1 wherein: the internal configuration of said primary amplifier issuch that a major portion of the fuel received at its power input isdirected to its second outlet during periods of engine idling when thepressure sensed in said cylinder is at its maximum, a minor portionbeing directed to the first power outlet of said first amplifier; andsaid primary amplifier directing proportionately more of said fuel toits first power outlet as the pressure in said cylinder decreases.
 3. Acarburetor as claimed in claim 2 wherein fuel flow into said firstsecondary amplifier is divided and flows out its first and second poweroutputs during periods of engine idle, said carburetor furtherincluding: a throttle valve in said cylinder; said second meansincluding a fluid passage connecting the second power outlet of saidfirst secondary amplifier to said cylinder downstream of said throttlevalve; and idle adjusting means for controlling the flow of fluidthrough said passage.
 4. A carburetor as claimed in claim 3 wherein saidfirst secondary fluid amplifier includes a third power outlet, saidpower outlets being positioned with respect to the power input andcontrol input whereby more fuel is delivered to said second and saidthird power outputs as pressure in said cylinder decreases.
 5. Acarburetor as claimed in claim 3 and further comprising: a secondcontrol input for said second secondary amplifier; and further means forapplying a signal to said second control input.
 6. A carburetor asclaimed in claim 5 wherein said further means comprises a fluid passagemeans terminating at an opening in said cylinder, and pressureregulating means in said fluid passage means.
 7. A carburetor as claimedin claim 5 wherein said further means comprise a normally closed fluidvalve, and means mechanically linked with said throttle valve foroperating said fluid valve, said fluid valve, when operated, connectingsaid second control input to the atmosphere.
 8. A carburetor as claimedin claim 5 wherein said further means comprise means for sensing thepressure downstream from said throttle valve, and valve means responsiveto said last named means for connecting said second control input to theatmosphere.
 9. A carburetor as claimed in claim 5 and furthercomprising: a source of fuel; means connecting said source to the powerinput of said primary amplifier; and means connected to said first poweroutputs of said secondary amplifiers for returning fuel to said source.